A space-saving, flexible, and easy to use clamping device for clamping multiple columns for a sample preparation is known from EP 2 767 828 B1, for example. The clamping device has multiple clamping blocks and a displacement mechanism for displacing a clamping block relative to an oppositely situated clamping block between an open position and a clamping position. In the open position, a column may be attached between two oppositely situated clamping blocks, while in the clamping position the inserted column is clamped between the oppositely situated clamping blocks in order to establish a fluid connection between the column and at least one of the oppositely situated clamping blocks. At least three clamping blocks are supported one behind the other in a row on a guide track, so that at least two columns may be clamped, one behind the other in the axial direction, between the clamping blocks. The slidable clamping blocks supported on the guide track are connected to the displacement mechanism via coupling means in such a way that actuation of the displacement mechanism from the clamping position into the open position causes displacement of all slidable clamping blocks, and in the process the columns are released.
Due to the arrangement of the clamping blocks on the guide track, the clamping device may be adapted very quickly and easily to different column lengths. Another advantage of the axial arrangement is that the fluid connection between the columns is comparatively short, if this is desired.
In the described embodiment, one of the clamping blocks is stationarily situated on the guide track, while at least two additional clamping blocks are slidably supported on the guide track. The clamping block stationarily situated on the guide track forms one end of the row of clamping blocks situated one behind the other, while at least the last slidable clamping block at the other end of the row is in operative connection with the displacement mechanism in order to displace it relative to the stationary clamping block. A displacement of the slidable clamping block, connected to the displacement mechanism, in the direction of the stationary clamping block also brings about a displacement of all clamping blocks situated in between, together with the inserted columns, until the clamping position is reached. It is thus possible to clamp a plurality of columns in a liquid-tight manner by displacing one clamping block. To limit the pressure generated by the clamping blocks on the columns, the displacement mechanism may have at least one force-limiting compensating spring, a displacement force generated by the displacement mechanism being transmitted to the at least one slidable clamping block via the compensating spring. Due to this compensating spring, the clamping force transmitted to the columns is limited, and overload/damage to the columns is thus avoided.